1. Field of the Invention
The invention relates to disk drives in computer systems. In particular the invention relates to disk drives in computer systems having private means for validating a key to enable features.
2. Description of the Related Art
Virtually all personal computer systems sold to users today include a disk drive for mass storage of programs and data. The user of the computer often has little awareness of the individual characteristics of the disk drive other than its storage capacity, hence he views the disk drive as an anonymous and generic component. The user""s view of the disk drive as anonymous and generic is encouraged by computer systems manufacturers, known as original equipment manufacturers (OEMs), because they prefer to source and integrate disk drives from multiple vendors at a fixed capacity point, and consequently discourage product differentiation by vendors. This practice severely limits the opportunities for a disk drive vendor to receive a return for features which they wish to include as a competitive advantage.
As an example, the storage capacity which can be provided by a disk drive may be primarily determined by the areal density which can be achieved with a given combination of heads, media, channel electronics, formatting and servo algorithms. As a disk drive matures during its production life, the potentially achievable areal density frequently increases significantly. However the business limitation of having to provide a fixed capacity point for integration into a computer system prevents the potentially increased capacity from being delivered.
Another problem is that the OEM may wish to dynamically change the mix of disk drive capacities in his product line, but is limited in his options to do so because he must commit to certain capacities far enough in advance to allow the disk drive suppliers to meet the demand.
Another problem is that users may find a need to upgrade the capacity of the disk purchased with their computer system, but are reluctant to do so because such upgrading requires opening the computer enclosure and performing tasks which they may find daunting.
Still another problem is that, although a disk drive vendor can develop and incorporate a number of features or improvements in his product which are potentially salable to an end user, the. anonymity of the disk drive in the computer system is a barrier and a viable and secure way to enable users to unlock the features or improvements has not heretofore been provided.
There is therefore a continuing need for a simple and secure means to enable disk drive or computer system manufacturers to provide enhanced features and product variations for which they can be compensated, while remaining compatible with the requirements of OEMs to have access to multiply sourced disk drives.
This invention can be regarded as a disk drive having a drive microprocessor and a means for drive-dependent identification. The means for drive-dependent identification are privately accessible by the drive microprocessor. The disk drive further comprises a means for receiving a key and a means for validating the key. The means for validating the key comprises a validation program which is privately accessed and executed by the drive microprocessor and a seed component. Preferably the seed component is derived from the means for drive-dependent identification.
In another aspect the invention can be regarded as disk drive having the above described key validation means and a physical capacity comprising an expansion portion and a user portion wherein the expansion portion has data sectors which can be converted to user portion data sectors when a key is validated.
The invention can also be regarded as a computer system having a host computer and a disk drive as described above wherein the host computer has a means for providing the key to disk drive.
In yet another aspect, the invention can be regarded as a method for validating a key for enabling a feature in a disk drive comprising the steps of receiving a key from the host computer; retrieving seed elements from a private area of the disk drive; generating an internal key in the disk drive; comparing the internal key to the key received from the host computer to determine if the received key is valid; and if the received key is valid, enabling the feature.